1. Field of the Invention
The present embodiment of the invention relates to portable computing devices and electronic documents, and in particular, user interfaces for the display and manipulation of document pages on portable computing devices.
2. Description of the Background Art
The use of portable computing devices has become commonplace for many users. In addition to having a conventional desktop computer, many users also have some type of portable computing device. Examples of present-day computing devices include electronic devices for reading such as the Reader from Sony Corp., the Kindle from Amazon, and the Nook from Barnes & Noble. Smaller portable computing devices include a plethora of smart phones including the iPhone from Apple Computer Inc., the Blackberry from Research In Motion and the Pre from Palm just to name a few. There have also been increased sales of notebook laptops and tablet computers offering different levels of processing capability and size.
One particular problem with such prior art devices is that they often do not include a keyboard. Even when they have a keyboard for input, it is typically not QWERTY keyboard but instead a 12-key telephone type keypad. Furthermore, most prior art devices do not include a stylus or similar pen-type input device. Therefore, manipulation of documents and the transition between displaying different pages can be difficult. For example, often the user has to transition one page at a time in order to traverse a document. When documents are hundreds of pages, search and document manipulation page by page can be limiting.
Another problem in the prior art is that the display area for the computing devices is often very limited. Since the devices have been constructed primarily for portability, there has been a compromise in design choice that has required the display size to be very small. For example, for smart phones the display size is often less than a small 3″×3″rectangle. Even for e-book readers, the display screen has less than a 7 inch diagonal. Therefore, the display screens typically only accommodate the display of a single page of a document. In general, there is limited if any ability to display multiple pages at the same time. Furthermore, as noted above these devices do not have a keyboard; and therefore, provide simple input buttons that allow the user to move to the next page or the previous page. Since most e-readers in the market do not include a stylus or pen-type input, use of these buttons is the only way to change the page that is being displayed by the reader.